Process for producing nickel carbonyl, nickel powder and use thereof

ABSTRACT

A process for producing Ni(CO) 4  from carbon monoxide and a source of nickel selected from the group consisting of elemental nickel, a nickel compound or mixtures thereof, provided the nickel compound is not nickel chloride per se or in admixture with a nickel carbonate ore, in an amount greater than 50% W/W nickel chloride; which process comprises (a) treating the nickel source with hydrogen at a pressure of at least atmospheric pressure and an effective temperature, in the presence of chloride anion or an in situ generator thereof precursor, to produce a resultant nickel; (b) reacting the carbon monoxide with the resultant nickel to produce the Ni(CO) 4 ; and collecting the Ni(CO) 4 . The process offers the production of Ni(CO) 4  at atmospheric pressure and at a sufficiently high rate for direct use in subsequent deposition processes without the need for storage facilities.

FIELD OF THE INVENTION

[0001] This invention relates to processes for producing nickelcarbonyl, more particularly to producing nickel powders of use inproducing said nickel carbonyl by reaction with carbon monoxide, and tosaid nickel powders made by said process.

BACKGROUND TO THE INVENTION

[0002] Nickel carbonyl, Ni(CO)₄ was first produced by the reaction ofmetallic nickel with carbon monoxide by Mond in the early part of the19^(th) century. Today, one of the major industrial processes for makingmetallic nickel is based on the production of Ni(CO)₄ and subsequentthermal decomposition thereof to Ni and CO. One known commercial processoperates at about 180° C. and a CO pressure of about 70 atm. It is knownthat the CO pressure may be reduced when the reactant nickel iscatalytically activated.

[0003] Activation of the metal has been observed in the presence ofmercury (1, 2), sulfur in the form of H₂S (3, 4), hydrogen (5, 6) orcarbon (7). It has been suggested that the high initial rate offormation of Ni(CO)₄ and the subsequent decline to a steady state valueis the result of a rapid decrease in the number of activated reactionsites which are produced upon heat treatment of the sample (8, 9, 6). Astudy of surface changes during carbonyl synthesis suggests that themaximum rate is associated with fundamental changes in the defectstructure. All of the above methods use catalytical activation of nickelin the presence of CO.

[0004] However, it can be readily appreciated that processes that atatmospheric pressure can produce nickel, particularly, activated nickelfor subsequent reaction with CO would provide significant capital andoperating cost advantages.

[0005] Further, it can also be appreciated that processes that enableNi(CO)₄ to be manufactured at a sufficient rate as to obviate the needfor storage in order to build up a sufficient supply for practical,efficient use in a subsequent nickel deposition process, would alsooffer significant capital and operating cost savings. To-date, incommercial operations rate limitations on the production of Ni(CO)₄require such storage facilities and operations.

[0006] There is, therefore, a need for an improved method of Ni(CO)₄production which is operably at atmospheric pressure and which is of asufficient rate as to negate the need for storage of the Ni(CO)₄ priorto use in a subsequent deposition process.

PUBLICATIONS

[0007] 1. Morton J. R., Preston K. F. J Chem. Phys., 81, 56, (1984).

[0008] 2. Morton J. R., Preston K. F. Inorg. Chem., 24, 3317, (1985).

[0009] 3. Mercer D. L.; Inco Ltd. (Can. 1038169 [1975/78]).

[0010] 4. Schafer H. Z. Anorg. Allg. Chem. 493, 17 (1982).

[0011] 5. Job R. J Chem. Educ. 56, 556 (1979).

[0012] 6. Mazurek H., Mehta R. S., Dresselhaus M. S., Dresselhaus G.,Zeiger H. J. Surf Sci. 118, 530 (1982).

[0013] 7. Korenev A. V., Shvartsman R. A., Mnukhin A. S., Tsvetn. Met.1979 No11, pp. 37.

[0014]8. Mehta R. S., Dresselhaus M. S., Dresselhaus G., Zeiger H. J.Surf Sci. 78, L681 (1978).

[0015] 9. Greiner G., Manzel D. J. Catal. 77 382 (1982).

SUMMARY OF THE INVENTION

[0016] It is an object of the present invention to provide a process forthe commercial production of Ni(CO)₄ from a source of nickel in anefficacious manner at atmospheric pressure, with resultant capital andoperation cost savings.

[0017] It is a further object of the present invention to provide aprocess for the commercial continuous production of Ni(CO)₄ from asource of nickel at a sufficiently high rate as to negate the need forstorage of the Ni(CO)₄ prior to a subsequent decomposition step, withresultant capital and operating cost savings.

[0018] Accordingly, in one aspect the invention provides a process forproducing Ni(CO)₄ from carbon monoxide and a source of nickel selectedfrom the group consisting of elemental nickel, a nickel compound ormixtures thereof, provided said nickel compound is not nickel chlorideper se or in admixture with a nickel carbonate ore, in an amount greaterthan 50% W/W nickel chloride; which process comprises (a) treating saidnickel source with hydrogen at a pressure of at least atmosphericpressure and an effective temperature, in the presence of chloride anionor an in situ generator thereof precursor, to produce a resultantnickel; and (b) reacting said carbon monoxide with said resultant nickelto produce said Ni(CO)₄.

[0019] By the term “resultant nickel” as used in this specification andclaims is meant resultant particulate nickel that reacts with CO atessentially atmospheric pressure and a temperature of at least 50° C. toeffect conversion to Ni(CO)₄ at an acceptable conversion rate.

[0020] By the term “acceptable conversion rate” is meant herein the rateof production of Ni(CO)₄ in the order of at least 0.5 g/hr Ni(CO)₄ perg/Ni. A more acceptable rate would be 1 g/hr Ni(CO)₄ per g/Ni and a moreefficacious rate for direct utilization, without the need for a build-upin storage, in a commercial subsequent deposition process would be atleast 10 g/hr Ni(CO)₄ per g/Ni.

[0021] The effective temperature is a temperature which effects theproduction of resultant nickel at an acceptable rate at at leastatomospheric pressure. Preferably, the effective temperature is in therange 300°-650° C. and more preferably, 350°-550° C.

[0022] The Ni(CO)₄ produced in step (b) may be collected, or,alternatively, when made at an acceptable conversion rate, preferably ofat least 10 g/hr Ni per g Ni, directly passed to a deposition chamberfor immediate decomposition to Ni and CO. This enables the CO to beimmediately recycled in a closed-loop manner as to provide a continuousCO closed-loop process.

[0023] The nickel compounds of use in the practice of the invention ashereinabove defined may readily be selected, from, but not limited to,for example, the group consisting of a nickel salt, carbonate,hydroxide, oxide and metallic elemental nickel. The metallic elementalnickel is most preferably in particulate form, for example, as a veryfine powder.

[0024] The chloride anion may be selected from, by way of example, butnot limited to, hydrogen chloride and a metallic chloride salt, such as,for example, an alkali, alkaline earth or transition metal simple orcomplex salt, e.g. FeCl₃. The invention also includes processes thatinvolve the use of precursors of chloride ion under the reactionconditions defined, such as, for example, suitable use of Cl₂, oxides ofchlorine gas and ⁻OCl₃ salts that produce chloride anion in situ.

[0025] The invention specifically excludes nickel chloride pr se alone,and admixtures thereof with nickel carbonate ores containing greaterthan 50% W/W nickel chloride.

[0026] The chloride anion is, preferably, present at a ratio of at least1:10 atomic W/W % Cl⁻ to Ni, more preferably 1:5 atomic W/W %.

[0027] A preferred process is wherein the chloride anion is present asgaseous hydrochloric acid in gaseous admixture with the hydrogen, andmore preferably, wherein the nickel compound is first treated withhydrogen at the effective temperature for a first period of time andsubsequently treated with the gaseous admixture for a second period oftime, at the effective temperature.

[0028] The chloride anion in alternative embodiments may be generated insitu under the aforesaid process conditions, according to the inventionas defined, in requisite effective amounts from chloride aniongenerating precursors, such as, for example, chlorate compounds andchlorine gas.

[0029] In a further aspect, the invention provides the resultant nickelwhen made by a process as hereinabove defined prior to its subsequentreaction with CO to from Ni(Co)₄.

[0030] We have found, further, that relatively small amounts of metalchlorides, e.g. ferric chloride in the presence of non-chloride nickelcompounds enable activated nickel to be formed according to the processof the invention hereinabove defined.

[0031] The gaseous product stream comprises H₂ and HCl and, optionally,H₂O, CO₂ and CO.

BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order that the invention may be better understood, preferredembodiments will now be described by way of example only with referenceto the accompanying drawing, wherein:

[0033]FIG. 1 is a graph showing overall conversion (%) against reactiontime (hr.) for various processes according to the invention; and

[0034]FIG. 2 is a diagrammatic flow diagram of a continuousself-contained process according to the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0035] In order that the invention may be better understood, preferredembodiments will now be described by way of example only, whereinExamples 1 and 2 do not constitute part of the invention as claimed butare provided for comparison purposes only.

EXAMPLE 1 (PRIOR ART)

[0036] NiCO₃ powder (200 g) was placed in an extraction reactor andtreated with a stream of H₂ gas at 300 mL/min flow rate, at 500° C. for7 hours to effect substantially complete reduction. The nickel powderproduced was cooled to 100° C. and the atmosphere of H₂ was subsequentlyreplaced with carbon monoxide. The reactor was cooled further to 50° C.and CO gas passed through at 300 mL/min flow rate. The resulting Ni(CO)₄was passed through a pair of carbonyl decomposers according to the priorart and nickel was recovered as nickel powder, (10 g; 20% yield) after12 hours.

EXAMPLE 2 (PRIOR ART)

[0037] Ni(OH)₂ powder (100 g) was placed in the extraction reactor andtreated with a stream of H₂ gas at 300 mL/min flow, at 500° C. for 7hours to essentially complete reduction. The resulting nickel powder wascooled to 100° C. in the atmosphere of H₂ which was subsequentlyreplaced with carbon monoxide. The reactor was cooled down further to50° C. and CO gas passed through at 300 mL/min flow rate. The resultingNi(CO)₄ gas was passed through carbonyl decomposers and nickel powder (6g, 9.5 yield) after 12 hours was recovered.

EXAMPLE 3

[0038] 300.1 g of a nickel carbonate/nickel chloride mixture (10:1 w/w)was placed into an extraction reactor and treated with hydrogen (2L/min) at 450° C. for 6 hours. Subsequently, the hydrogen was replacedwith argon, the reactor cooled to 40° C. and the argon replaced withcarbon monoxide at a gas temperature of 80° C., and flow rate of 4L/min. whereby nickel carbonyl was formed, collected and subsequentlydecomposed to Ni and CO to provide (103 g; 70%) yield of nickelextraction yield in 6 hr.

EXAMPLE 4

[0039] 302.3 g of the same mixture as in Example 3 was treated undersimilar conditions but wherein after 0.5 h, the hydrogen gas was dopedwith 1% of HCl for a further reaction period of 4 hours. The subsequentnickel extraction procedure was similar to Example 3 and gave 134 g; 90%yield of nickel in 6 h.

EXAMPLE 5

[0040] 300.1 g of nickel carbonate was treated under similar conditionsas in Example 4 but wherein after 0.5 h a flow of 900 cc/min of HCl gaswas introduced into the hydrogen flow at 2 L/min for 4 h. The subsequentnickel extraction procedure was similar to Example 3 and gave a 96.48%yield of nickel in 13 h.

[0041] The aforesaid examples 3-5 are better illustrated with referenceto FIG. 1 wherein:

[0042] Line 1 represents the carbonylation of nickel produced by thereaction of a mixture of nickel carbonate/nickel chloride 10:1. (6 h,70.4% yield) according to Example 3.

[0043] Line 2 represents the same composition according to line 1 plus1% pf HCl in the gas stream (6 hours, 90.45% yield) according to Example4; and

[0044] Line 3 represents 100% nickel carbonate plus HCl (13 h, 96.48%)according to Example 5.

[0045] The aforesaid examples clearly illustrate the beneficial effectof having chloride anion present in admixture with a nickel compound inthe hydrogen reactor in producing a particulate nickel more efficaciousin reacting with CO to produce Ni(CO)₄. TABLE 1 Rate** Exam- Ni CompoundEquivalent Deposited Time gNi/gNi/hr ple (g) Ni (g) Ni (g) (hr)**(approx.) #1 200 (NiCO₃) 49 10 12 0.01 #2 100 (Ni(OH₂)) 63 6 12 0.01 #3300 NiCO₃/ 147 103 6 1.17 NiCl₂ (10:1) #4 302 NiCO₃/ 148 134 6 15 NiCl₂(10:1) #5 300 g NiCO₃ 148 142 13 7.4

[0046] Table 1 shows the beneficial enhancement in the rate ofproduction of Ni from its various sources by the process according tothe present invention, wherein the presence of chloride anion inExamples 3, 4 and 5 shows the very significant beneficial effect overthe absence of chloride anion in Examples 1 and 2.

[0047] This enhancement in production rate of Ni(CO)₄ enables the directuse thereof in any subsequent desired decomposition step.

[0048]FIG. 2 is a diagrammatic flow diagram of a continuous nickeldeposition process self-contained with respect to CO, according to theinvention. It shows generally as 10, a reaction chamber 12 linked todecomposition chamber 14 by Ni(CO)₄ and CO conduits 16 and 18,respectively.

[0049] Chamber 12 contains, alternatively, nickel source 20 andresultant nickel 22; and has hydrogen feed and outlet/recycle conduits24 and 26, respectively; HCl feed and outlet/recycle conduits 28 and 30,respectively; and Ni(CO)₄/CO exit conduit 16. Decomposition chamber 14contains a substrate 32 to be coated by Ni(CO)₄ from line 16.

[0050] In operation, nickel source 20 is treated with hydrogen,typically, at 400-500° C. for 5-15 hours and 2 l/min at atmospherepressure to produce a reduced nickel powder 21.

[0051] HCl gas at 1 l/min and 50-80° is then recycled through chamber12, optionally, with hydrogen, to produce treated nickel powder 22.Chamber 12 is then subsequently purged with, for example, argon fromconduit 23 and, thereafter, CO from conduit 18 is fed into chamber 12,wherein Ni(CO)₄ is produced and passed through conduit 16 todecomposition chamber 14. Recycle conduit as shown in FIG. 2 areutilized as desired.

[0052] It can be seen that once the process is operating at “steadystate” for an alternative two-stage operative cycle, that the amount ofCO used in the production of Ni(CO)₄ can be met from the decompositionthereof in chamber 14. The process can thus be considered as beingessentially self-contained with respect to CO.

[0053] Importantly, since the rate of production of Ni(CO)₄ in chamber12 is sufficiently high enough to warrant a direct feed to chamber 14for decomposition of Ni onto substrate 32 in an efficacious manner, nointervening storage facility is required. This is of value in commercialoperations.

[0054] Although this disclosure has described and illustrated certainpreferred embodiments of the invention, it is to be understood that theinvention is not restricted to those particular embodiments. Rather, theinvention includes all embodiments which are functional or mechanicalequivalents of the specific embodiments and features that have beendescribed and illustrated.

1. A process for producing Ni(CO)₄ from carbon monoxide and a source ofnickel selected from the group consisting of elemental nickel, a nickelcompound or mixtures thereof, provided said nickel compound is notnickel chloride per se or in admixture with a nickel carbonate ore, inan amount greater than 50% W/W nickel chloride; which process comprises(a) treating said nickel source with hydrogen at a pressure of at leastatmospheric pressure and an effective temperature, in the presence ofchloride anion or an in situ generator thereof precursor; to produce aresultant nickel; and (b) reacting said carbon monoxide with saidresultant nickel to produce said Ni(CO)₄.
 2. A process as defined inclaim 1 wherein said nickel compound is selected from the groupconsisting of a nickel salt, nickel hydroxide, nickel carbonate andnickel oxide.
 3. A process as defined in claim 1 wherein said chlorideanion is present from a compound selected from hydrogen chloride and ametallic chloride.
 4. A process as defined in claim 3 wherein saidmetallic chloride is selected from the group consisting of an alkali,alkaline earth and transition metal chloride.
 5. A process as defined inclaim 2 wherein said chloride anion is present as gaseous hydrochloricacid in gaseous admixture with said hydrogen.
 6. A process as defined inclaim 5 wherein said nickel compound is firstly treated with hydrogen atsaid effective temperature for a first period of time and subsequentlytreated with said gaseous admixture for a second period of time, at saideffective temperature.
 7. A process as defined in claim 6 wherein saidnickel compound is nickel carbonate and said gaseous admixture comprisesHCl and H₂ in the ratio of about 1:2.
 8. A process as defined in claim 7wherein said nickel compound is nickel carbonate.
 9. A process asdefined in claim 1 wherein said effective temperature is selected fromthe range 300°-650° C.
 10. A process as defined in claim 9 wherein saideffective temperature is selected from 350°-550° C.
 11. A process asdefined in claim 1 wherein said resultant nickel is reacted with carbonmonoxide at a temperature of about 50° C.
 12. A process as defined inclaim 1 wherein said Ni(CO)₄ is produced in step (b) at an acceptableconversion rate, and further comprising passing said Ni(CO)₄ directly toa decomposition chamber and decomposing said Ni(CO)₄ to deposit nickeland CO.
 13. A process as defined in claim 12 wherein said acceptableconversion rate is at least 10 g/hr Ni(CO)₄ per g Ni.
 14. A process asdefined in claim 1 wherein said precursor is selected from the groupconsisting of Cl₂, oxides of chlorine and NaOCl.
 15. A process forproducing a resultant treated nickel compound of subsequent use in theproduction of Ni(CO)₄ by reaction with carbon monoxide, from a nickelsource selected from the group consisting of elemental nickel, a nickelcompound or mixtures thereof, provided said nickel compound is notnickel chloride per se or in admixture with a nickel carbonate ore, inan amount greater than 50% W/W nickel chloride; which process comprises(a) treating said nickel source with hydrogen at a pressure of at leastatmospheric pressure and an effective temperature, in the presence ofchloride anion or an in situ generator thereof precursor; and collectingsaid resultant nickel.
 16. A process as defined in claim 15 wherein saidnickel compound is selected from the group consisting of a nickel salt,nickel hydroxide, nickel carbonate and nickel oxide.
 17. A process asdefined in claim 15 wherein said chloride anion is present from acompound selected from the group consisting of hydrogen chloride and ametallic chloride.
 18. A process as defined in claim 17 wherein saidmetallic chloride is selected from the group consisting of an alkali,alkaline earth and transition metal chloride.
 19. A process as definedin claim 17 wherein said chloride anion is present as gaseoushydrochloric acid in gaseous admixture with said hydrogen.
 20. A processas defined in claim 19 wherein said nickel compound is firstly treatedwith hydrogen at said effective temperature for a first period of timeand subsequently treated with said gaseous admixture for a second periodof time, at said effective temperature.
 21. A process as defined inclaim 20 wherein said nickel compound is nickel carbonate said gaseousadmixture comprises HCl and H₂ in the ratio of about 1:2.
 22. A processas defined in claim 21 wherein said nickel compound is nickel carbonate.23. A process as defined in claim 15 wherein said effective temperatureis selected from the range 300°-650° C.
 24. A process as defined inclaim 23 wherein said effective temperature is selected from 350°-550°C.
 25. A process as defined in claim 15 wherein said precursor isselected from the group consisting of Cl₂, oxides of chlorine and ⁻OClsalts.
 26. A resultant nickel produced by a process as defined in claim15.